Grate-bar.



E. L. THOMAS.

GRATE BAR.

APPLICATION FILED APR.25, 1911.

Patented Oct. 14, 1913.

.. dzaafd 6 EDWARD L. THOMAS, OF VALDOSTA, GEORGIA.

GRATE-BAR.

Specification of Letters Patent.

Patented'Oct. 14, 1913.

Application filed April 25, 1911. Serial No. 623,229.

To all whom it may concern:

Be it known that I, EDWARD L. THOMAS, a citizen of the United States, residing at Valdosta, in the county of Loundes and State of Georgia, have invented new and useful Improvements in Grate- Bars, of which the following is a specification. I

This invention relates to improvements in grate bar units and it is designed more particularly as an improvement upon the construction disclosed in my U. S. Letters Patent, No. 949,639, of Feb. 15,1910.

The invention proposes a grate bar unit which is especially intended for use in connection with the so-called Dutch oven furnaces or fire boxes wherein the fuel is piled to a great depth, usually from two to five feet, upon the grate. To the best of my knowledge, which is based on a long and comprehensive practical experience, no grate bar unit has been originated which may be said to be satisfactory in a furnace or fire box of the type referred to. The reason for this is that the fuel i's piled to a great depth, as stated, and is usually impregnated with sand or extraneous matter which, becoming molten in the heavy fuel bed, runs together in a sticky, gummy mass and forms glass and clinker. This substance is produced to such an extent that it spreads over the whole fuel supporting surface of the grate, finding lodgmentin the'vari'ous open ings and crevices, obstructing the draft spaces, seriously interfering with the steaming of the plant, and burning the bars.

The primary object of the present invention is to overcome the objections noted in the preceding paragraph and in furtherance of this object the invention proposes a grate bar unit which, while proceeding generally upon the lines indicated in my prior patent referred to, embodies a new and improved fuel supporting structure which is characterized essentially by the provision of a number of longitudinal parallel bars designed and constructed to facilitate the discharge of the molten extraneous matter and to prolong the eih'cient life of the unit as a whole.

The above and other objects will appear as the description proceeds.

An embodiment of the I invention is illustrated in the accompanying drawings, wherein V Figure 1 is a plan view showing the fuel supporting bars in detached relation. ig.

2 is a perspective view of a grate bar unit in accordance with the present invention, the fuel supporting bars being omitted. Fig. 3 isa planview thereof. Fig. 4 is a side elevation thereof. Fig. 5 is an end View thereof, and Fig. 6 is a cross sectional view thereof.

Similar characters of reference designate corresponding parts throughout the several views.

' The improved grate bar unit comprises an upper-portion designated generally by the numeral l and a lower portion designated generally by the numeral 2. The upper portion '1 is the improved fuel supporting portion and consistsessentially of a rectangular frame as 3 and a plurality of longitudinally disposed fuel supporting bars, as 4. The lower portion 2, which may also be used as a fuel supporting portion (although not in connection with Dutch oven furnaces or fire boxes) is in the present construction essentially a supporting and strengthening means for the fuel supporting portion 1. The lower portion 2 consists preferably of a pair of longitudinal side bars 5, a longitudinal intermediate bar 6, and cross bars 7 connecting the bars 5 and 6. The bar '6 is located in a lowerplane than the bars 5 and the connecting bars 7 are curved, whereby the portion 2 has a semi-oval or semi-elliptical cross section which is conducive to great strength. The intervals between the bars 7 are of such extent that the openings 8, which are afforded, are amply suflicient to provide for the shedding of the molten extraneous and clinker-making matter, which runs from the fuel supporting bars.

The side bars of the frame 8 and the side bars 5 are connected by lugs 9, which provide for circulation spaces 10 between the portions v1 and 2, and thus serve not only as a connection between the opposed portions of each unit but also as a means for maintaining the proper spacing of these opposed portions and for preventing the transmission of heat from the upper fuel supporting portion '1 to the lower strengthening portion 2. The side bars of the frame 3 are also provided with, outwardly projecting lugs 11, which serve to space the mutually adjacent units from one another and to thus provide for a natural circulation-of air from the ash pit through the grate.

' The bars 4 are preferably and advantageously separable from the unit with which they are associated. This relation renders it possible to make the bars of steel and to secure several substantial advantages to be hereafter referred to. To support the bars 4:, cross bars 12 are employed, these cross bars having alining recesses 13, in which the several bars 4: seat. The bars 12 are preferably arranged coincidentally with the lugs 11 and the bars 5, this arrangement mani festly conducing to greater strength and rigidity. The bars 4: preferably have a round cross section and have a degree of association which, while not in any way interfering with the efficiency of the fuel supporting surface, adequately provides for the pas sage of molten matter through the spaces 14, which intervene between said bars. The bars 4c, by virtue of their position and association provide a substantial, indestructible and rigid support for the fuel, and on account of their comparatively small diameter and curved cross section furnish no lodgment for molten clinker making matter, such matter crawling from said bars through the openings 14: and ultimately dropping into the ash pit through the openings 8. In case any of the molten matter clings to the bars 4 they can be removed as soonas the fire burns down and other clean bars substituted, the bars which are removed being allowed to cool and then cleaned by scraping. In like manner the unit itself may be taken from the grate and, the bars 4 having been removed, may be readily cleaned by scraping therefrom any molten matter which may have adhered. The bars 4 being of steel, as distinguished from cast metal, have a very long, etiicient life, and it is manifest that by having a double set of these bars, removing the used set every night and substituting the cleaned set, itis possible to have a clean grate every day. The bars 4, in addition to the advantages above stated prolong the life of the unit as a whole, since they take up the major portion of the heat and thus prevent the cast body part of the unit from coming hot, crystallized, or worn, it being noted that the said cast body part also possesses the advantages set forth in my prior patent referred to. Further advantages of the bars 4t are (1 that when said bars are carelessly placed in position, they automatically roll or fall .into the seats afforded by the recesses 13; (2) that, owing to their loose and independent assemblage, any individual bar may be displaced or flipped up by a suitable instrument without effort or loss of time to allow any large lump of foreign non-combustible matter to fall through to the ash pit; (3) that if it is necessary on account of conditions to vary the size of the draft spaces, bars of larger or of smaller diameter as required may be substituted and (4:) that, owing to the roundness and smoothness of the surface of the bars, they are, substantially, self cleaning as to molten and clinker-making matter.

It will be apparent from the foregoing description that the grate bar unit herein proposed is of indestructible nature; has great strength and furnishes an eflicient support for the fuel bed; promotes the circulation of airvboth vertically and horizontally through the grate, and makes provision for the renewal, cleaning and substitution of its fuel supporting parts.

WVhile the improved grate bar unit is especially applicable to Dutch oven furnaces, it will be understood that it may be used with equal facility in connection with furnaces of other types.

I claim as my invention:

1. A grate bar unit comprising a cast body part having a fuel supporting portion which includes a series of openly recessed cross bars and a plurality of parallel longitudinal, circularly cross-sectioned, steel, fuel-supporting bars of uniform diameter throughout their extent, fitted loosely and independently in the recesses of the cross bars, and being removable from said body part by upward displacement.

2. A grate bar unit comprising a body part having an upper rectangular frame, and recessed cross bars connecting the side. bars of the frame; a lower portion which includes side bars, an intermediate bar below the side bars, and cross bars connecting the side bars and the intermediate bar; spaced lugs integrally'connecting the side bars of the frame and the last named side bars; and parallel steel fuel-supporting bars disposed longitudinally and loosely seated in the recesses of the cross bars.-

3. A grate bar unit comprising a cast body part having an upper rectangular frame and recessed cross bars connecting the side bars of the frame; a lower portion of semi-elliptic cross section and 1 skeleton construction; spaced lugs integrally connecting the side bars of the frame and said lower portion; and parallel steel fuel-supporting bars disposed longitudinally and loosely'seated in the recesses of the cross bars.

4. A grate bar unit which comprises a cast skeleton lower port-ion of inverted arch shape, a plurality of openly recessed cross bars oined integrally to said lower portion,

and a plurality of structurally independent parallel longitudinal fuel supporting bars fitted loosely in the recesses of the cross bars, and being removable therefrom by upward displacement.

5. A grate bar unit which comprises a cast skeleton lower portion of inverted arch shape, aplurality of openly recessed cross bars joined integrally to said lower portion, and a plurality of parallel longitudinal circularly cross sectioned steel fuel supporting bars fitted loosely and independently in the recesses of the cross bars and being removable from said body part by upward displacement.

6. A grate bar unit which comprises a cast skeleton lower portion of inverted arch shape, having at its upper end a rectangular frame and at its center a longitudinally disposed upwardly projecting reinforcing rib, and a plurality of spaced parallel fuel supporting members having rounded fuel engaging surfaces, said members being supported by said rectangular frame and being fitted loosely and independently relatively thereto.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

EDWARD L. THOMAS. Witnesses:

C. T. Fox, L. H. WARLICK.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

